Reduced genetic diversity associated with the northern expansion of an amphibian species with high habitat specialization, , resolved using two types of genetic markers.

Reconstruction of historical relationships between geographic regions within a species' range can indicate dispersal patterns and help predict future responses to shifts in climate. (coastal tailed frog) is an indicator species of the health of forests and perennial streams in the Coastal and Cascade Mountains of the Pacific Northwest of North America. We used two genetic techniques-microsatellite and genotype-by-sequencing (GBS)-to compare the within-region genetic diversity of populations near the northern extent of the species' range (British Columbia, Canada) to two geographic regions in British Columbia and two in Washington, USA, moving toward the core of the range.